Geologically, Warm Mineral Springs is a solution hole descending into one of the deepest Florida aquifers. The water flowing from this spring is anaerobic (low in oxygen) and is believed to have been trapped underground for over thirty thousand years at depths exceeding 7000 feet. Under these great pressures, the water is geothermally heated to 97º degrees Fahrenheit and flows from several small caves located on the northern wall at depths from 195 to 210 feet. As the water rises towards the surface, it mixes with cooler water from colder vents. When it reaches the surface, the temperature drops to 85º degrees Fahrenheit. Eight million gallons of water a day flow down a natural run on the surface and eventually into the Gulf of Mexico.

Diving Warm Mineral, Noticeably unique during the descent is the amount of bacteria covering every inch of the sink. Dropping to 20 feet, we place our oxygen cylinders on the pre-made PVC decompression rack, which is attached to the wall from 10 down to 40 feet. Just off the deco rack is a down line that takes us under the 70-foot lip where we attach our nitrox 50 percent for decompression from the 70 to 30 foot stops. Descending, we follow the wall as it undercuts sharply down into the darkness. At a depth of 175 feet, we hit a reverse thermocline and the water temperature instantly goes from 84 to 97 degrees, with the visibility increasing to over 80 feet. Reaching the bottom at 205 feet, hot water can be seen flowing from several small vents along the walls.

Turning to the right, we quickly come upon the main cave system connected to the sink. Most of the water flows from this system. The entrance to the cave is just large enough to squeeze though with a set of doubles. Extreme caution must be taken to not disturb the thick silt on the floor. There the small cave makes a sharp turn to the left. After 150 feet of back-to-belly passage, the cave opens into a room where multiple smaller vents flow. This room is 25 feet long, 10 feet tall, and 10 feet wide with white chalky walls and a maximum depth of 223 feet.